This invention relates to a class of ligand or complex thereof useful as catalysts for catalytically bleaching substrates in an environment substantially devoid of peroxyl species.
The use of bleaching catalysts for stain removal has been developed over recent years. The recent discovery that some catalysts are capable of bleaching effectively in the absence of an added peroxyl source has recently become the focus of some interest, for example: WO9965905; WO0012667; WO0012808, and WO0029537.
The search for new classes of compounds that are suitable as xe2x80x9cair bleachingxe2x80x9d catalysts is ongoing.
Various [3.3.1] bicyclo compounds and complexes thereof are discussed in the literature, see for example: Comba P. et al., J. Chem. Soc. Dalton Trans, 1998, (23) 3997-4001; Bxc3x6rzel et al. Chem. Eur. J. 1999, 5, No. 6, 1716 to 1721 and review by P. Comba in Coordination Chemistry Reviews 2000, 200-202, 217 to 245, entitled xe2x80x9cCoordination compounds in the Entactic Statexe2x80x9d. These compounds are discussed in terms of their physical properties.
WO0060045 discloses a bleaching system comprising: a) from about 1 ppb, by weight of a transition metal catalyst comprising: i) a transition metal; ii) a ligand having formula (I): 
wherein each R is independently hydrogen, hydroxyl, C1-C4 alkyl, and mixtures thereof; R1 is C1-C4 alkyl, C6-C10 aryl, and mixtures thereof; R2 is C1-C4 alkyl, C6-C10 aryl, and mixtures thereof; R3 and R4 are each independently hydrogen, C1-C8 alkyl, C1-C8 hydroxyalkyl, xe2x80x94(CH2)xCO2R5 wherein R5 is C1-C4 alkyl, x is from 0 to 4, and mixtures thereof; X is carbonyl, xe2x80x94C(R6)2xe2x80x94 wherein each R6 is independently hydrogen, hydroxyl, C1-C4 alkyl, and mixtures thereof; b) optionally a source of hydrogen peroxide; and c) the balance carriers and adjunct ingredients. However, the teaching of WO0060045 limits substituents at the nitrogens (3 and 7 positions) of bicyclostructure to homoaromatic carbon groups, namely alkyl and aryl. The general structure of Formula (I) is referred to as a bispidon.
The bleaching of a stain by a peroxyl species is aided by the presence of an active transition metal catalyst. A peroxyl species commonly found in laundry bleaching compositions is hydrogen peroxide (H2O2) or a precursor thereof, e.g., sodium percarbonate or sodium perborate. In many instances an activator/precursor, e.g., TAED (tetraacetylethylene diamine), is present which serves together with hydrogen peroxide to form a peracid [RC(O)OOH] to facilitate bleaching.
Recently we have found that oily stains are bleached in the presence of selected transition metal catalysts in the absence of an added peroxyl source. The bleaching of an oily stain in the absence of an added peroxyl source has been attributed to oxygen derived from the air. Whilst it is true that bleaching is effected by oxygen sourced from the air the route in which oxygen plays a part is becoming understood. In this regard, the term xe2x80x9cair bleachingxe2x80x9d is used.
We have concluded from our research that bleaching of a chromophore in an oily stain is effected by products formed by adventitious oxidation of components in the oily stain. These products, alkyl hydroperoxides, are generated naturally by autoxidation of the oily stain and the alkyl hydroperoxides together with a transition metal catalyst serve to bleach chromophores in the oily stain. Alkyl hydroperoxides (ROOH) are generally less reactive that other peroxy species, for example, peracids (RC(O)OOH), hydrogen peroxide (H202), percarbonates and perborates.
Our earlier filed application PCT/EP01/13314, filed 5, Nov. 2002, which claims priority from GB0030673.8, filed 15, Dec. 2000, discloses the use of various bispidon compounds. Referring to the structure above, PCT/EP01/13314 teaches that there is an advantage to be secured by having at least one of R1and R2 as group containing a heteroatom capable of coordinating to a transition metal. We have now found that by having at least one of R1and R2 as a group that is a tertiary amine linked to one or more of the nitrogen atoms of the bicyclo structure by a C2 to C4 alkyl chain further advantages are secured. In addition, we have also found that heterocycles other than pyridyl may be used at the 2 and 4 positions.
Accordingly, in a first aspect, the present invention provides a bleaching composition comprising:
A bleaching composition comprising:
a) a monomer ligand, L, or transition metal catalyst thereof of a ligand having the formula (I): 
wherein at least one of R1 and R2 is an optionally substituted tertiary amine of the form xe2x80x94C2-C4-alkyl-NR7R8, in which R7 and R8 are independently selected from the group alkyl, benzyl, the xe2x80x94C2-C4-alkyl- of the xe2x80x94C2-C4-alkyl-NR7R8 may be substituted by 1 to 4 C1-C2-alkyl, or may form part of a C3 to C6 alkyl ring, and in which R7 and R8 may together form a saturated ring containing one or more other heteroatoms, the other of R1 and R2 being independently selected from:
xe2x80x94C2-C4-alkyl-NR7R8 as defined above,
xe2x80x94C1-C24-optionally subsituted-alkyl,
xe2x80x94C6-C10-aryl, xe2x80x94C1-C4-alkyl-C6-C10-aryl,
a heterocycloalkyl: selected from the group consisting of: pyrrolinyl, pyrrolidinyl, morpholinyl, piperidinyl, piperazinyl, hexamethylene imine, 1,4-piperazinyl, tetrahydrothiophenyl, tetrahydrofuranyl, tetrahydropyranyl, and oxazolidinyl, wherein the heterocycloalkyl may be connected to the ligand via any atom in the ring of the selected heterocycloalkyl, a xe2x80x94C1-C6-alkyl-heterocycloalkyl, wherein the heterocycloalkyl of the xe2x80x94C1-C6-heterocycloalkyl is selected from the group consisting of: piperidinyl, piperidine, 1,4-piperazine, tetrahydrothiophene, tetrahydrofuran, pyrrolidine, and tetrahydropyran, wherein the heterocycloalkyl may be connected to the xe2x80x94C1-C6-alkyl via any atom in the ring of the selected heterocycloalkyl, a xe2x80x94C1-C6-alkyl-heteroaryl, wherein the heteroaryl of the xe2x80x94C1-C6-alkylheteroaryl is selected from the group consisting of: pyridinyl, pyrimidinyl, pyrazinyl, triazolyl, pyridazinyl, 1,3,5-triazinyl, quinolinyl, isoquinolinyl, quinoxalinyl, imidazolyl, pyrazolyl, benzimidazolyl, thiazolyl, oxazolidinyl, pyrrolyl, carbazolyl, indolyl, and isoindolyl, wherein the heteroaryl may be connected to the xe2x80x94C1-C6-alkyl via any atom in the ring of the selected heteroaryl and the selected heteroaryl is optionally substituted by xe2x80x94C1-C4-alkyl, xe2x80x94C0-C6-alkyl-phenol, xe2x80x94C0-C6-alkyl-thiophenol, xe2x80x94C2-C4-alkyl-thiol, xe2x80x94C2-C4-alkyl-thioether, xe2x80x94C2-C4-alkyl-alcohol, xe2x80x94C2-C4-alkyl-amine, and a xe2x80x94C2-C4-alkyl-carboxylate;
R3 and R4 are independently selected from hydrogen, C1-C4-alkyl, phenyl, electron withdrawing groups and reduced products and derivatives thereof;
X is selected from: Cxe2x95x90O, a ketal derivative of Cxe2x95x90O, a thioketal of derivative of Cxe2x95x90O, and xe2x80x94[C(R6)2]yxe2x80x94 wherein y takes a value 0 or 1; each R6 is independently selected from hydrogen, hydroxyl, Oxe2x80x94C1-C24-alkyl, O-benzyl, Oxe2x80x94(Cxe2x95x90O)xe2x80x94C1-C24-alkyl, C1-C24-alkyl;
z groups are same heteroaromatic groups, selected from the group consisting of: pyridinyl; pyrimidinyl; pyrazinyl; triazolyl; pyridazinyl; 1,3,5-triazinyl; quinolinyl; isoquinolinyl; quinoxalinyl; imidazolyl; pyrazolyl; benzimidazolyl; thiazolyl; oxazolidinyl; pyrrolyl; carbazolyl; indolyl; and isoindolyl, and the selected Z is optionally substituted by xe2x80x94C1-C4-alkyl;
b) the balance carriers and adjunct ingredients.
In a second aspect, the present invention provides a bleaching composition comprising, in an aqueous medium, the bicyclo ligand of the general Formula (I) which forms a complex with a transition metal, the complex catalysing bleaching of a substrate, wherein the aqueous medium is substantially devoid of peroxygen bleach or a peroxy-based or -generating bleach system. It is preferred that the medium has a pH value in the range from pH 6 to 12 and most preferably from pH 8 to 11.
The term xe2x80x9csubstantially devoid of a peroxygen bleach or a peroxy-based or peroxyl-generating bleach systemxe2x80x9d should be construed within spirit of the invention. It is preferred that the composition has as low a content of peroxyl species present as possible. It is preferred that the bleaching formulation contains less that 1% wt/wt total concentration of peracid or hydrogen peroxide or source thereof, prefereably the bleaching formulation contains less than 0.3% wt/wt total concentration of peracid or hydrogen peroxide or source thereof, most preferably the bleaching composition is devoid of peracid or hydrogen peroxide or source thereof.
An advantage of the class of ligand and complex according to the present invention is that the complex can catalyse bleaching of a substrate via atmospheric oxygen, thus permitting its use in a medium such as an aqueous medium that is substantially devoid of peroxygen bleach or a peroxy-based or -generating bleach system. We have also found that complexes of this class are surprisingly effective in catalysing bleaching of the substrate via atmospheric oxygen after treatment of the substrate.
One skilled in the art will appreciate that not all peroxyl activating catalysts are capable of providing discernable bleaching activity with adventitious hydroperoxides present in a stain. However, the converse is not true. There is no evidence to indicate that any xe2x80x9cair bleachingxe2x80x9d catalyst will not function as peroxyl activating catalyst. In this regard, all xe2x80x9cair bleachingxe2x80x9d catalysts disclosed herein may be used as a peroxyl activating catalyst. Catalysts of the present invention may be incorporated into a composition together with a peroxyl species or source thereof. For a discussion of acceptable ranges of a peroxyl species or source thereof and other adjuvants that may be present the reader is directed to U.S. Pat. No. 6,022,490, the contents of which are incorporated by reference.
The present invention extends to a method of bleaching a substrate comprising applying to the substrate, in an aqueous medium, the bleaching composition according to the present invention.
The present invention extends to a commercial package comprising the bleaching composition according to the present invention together with instructions for its use.
The present invention further provides a dry textile having an organic substance as defined above applied or deposited thereon, whereby bleaching via atmospheric oxygen derived alkylhydroperoxides is catalysed on the textile.
Advantageously, by enabling a bleaching effect even after the textile has been treated, the benefits of bleaching can be prolonged on the textile. Furthermore, since a bleaching effect is conferred to the textile after the treatment, the treatment itself, such as a laundry wash cycle, may for example be shortened. Moreover, since a bleaching effect is achieved via atmospheric oxygen after treatment of the textile, hydrogen peroxide or peroxy-based bleach systems can be omitted from the treatment substance.
The organic substance may be contacted to the textile fabric in any suitable manner. For example, it may be applied in dry form, such as in powder form, or in a liquor that is then dried, for example as an aqueous spray-on fabric treatment fluid or a wash liquor for laundry cleaning, or a non-aqueous dry cleaning fluid or spray-on aerosol fluid. Other suitable means of contacting the organic substance to the textile may be used, as further explained below.
Any suitable textile that is susceptible to bleaching or one that one might wish to subject to bleaching may be used. Preferably the textile is a laundry fabric or garment.
In a preferred embodiment, the treated textile is dried, by allowing it to dry under ambient temperature or at elevated temperatures. The elevated temperatures are commonly provided by a heated agitated environment, as for example found in a tumble dryer, which has been found to accelerate and enhance the xe2x80x9cair bleachingxe2x80x9d effect.
The organic substance can be contacted with the textile fabric in any conventional manner. For example it may be applied in dry form, such as in powder form, or in a liquor that is then dried, for example in an aqueous spray-on fabric treatment fluid or a wash liquor for laundry cleaning, or a non-aqueous dry cleaning fluid or spray-on aerosol fluid.
In a particularly preferred embodiment the method according to the present invention is carried out on a laundry fabric using aqueous treatment liquor. In particular the treatment may be effected in, or as an adjunct to, an essentially conventional wash cycle for cleaning laundry. More preferably, the treatment is carried out in an aqueous detergent wash liquor. The organic substance can be delivered into the wash liquor from a powder, granule, pellet, tablet, block, bar or other such solid form. The solid form can comprise a carrier, which can be particulate, sheet-like or comprise a three-dimensional object. The carrier can be dispersible or soluble in the wash liquor or may remain substantially intact. In other embodiments, the organic substance can be delivered into the wash liquor from a paste, gel or liquid concentrate.
It is particularly advantageous that the organic substance used in the method of the present invention makes use of atmospheric oxygen in its bleaching activity. This avoids the requirement that peroxygen bleaches and/or other relatively large quantities of reactive substances need be used in the treatment process. Consequently, only-a relatively small quantity of bleach active substance need be employed and this allows dosage routes to be exploited that could previously not be used. Thus, while it is preferable to include the organic substance in a composition that is normally used in a washing process, such as a pre-treatment, main-wash, conditioning composition or ironing aid, other means for ensuring that the organic substance is present in the wash liquor may be envisaged.
For example, it is envisaged that the organic substance can be presented in the form of a body from which it is slowly released during the whole or part of the laundry process. Such release can occur over the course of a single wash or over the course of a plurality of washes. In the latter case it is envisaged that the organic substance can be released from a carrier substrate used in association with the wash process, e.g. from a body placed in the dispenser drawer of a washing machine, elsewhere in the delivery system or in the drum of the washing machine. When used in the drum of the washing machine the carrier can be freely moving or fixed relative to the drum. Such fixing can be achieved by mechanical means, for example by barbs that interact with the drum wall, or employ other forces, for example a magnetic force. The modification of a washing machine to provide for means to hold and retain such a carrier is envisaged similar means being known from the analogous art of toilet block manufacture. Freely moving carriers such as shuttles for dosage of surfactant materials and/or other detergent ingredients into the wash can comprise means for the release of the organic substance into the wash.
In the alternative, the organic substance can be presented in the form of a wash additive that preferably is soluble. The additive can take any of the physical forms used for wash additives, including powder, granule, pellet, sheet, tablet, block, bar or other such solid form or take the form of a paste, gel or liquid. Dosage of the additive can be unitary or in a quantity determined by the user. While it is envisaged that such additives can be used in the main washing cycle, the use of them in the conditioning or drying cycle is not hereby excluded.
The present invention is not limited to those circumstances in which a washing machine is employed, but can be applied where washing is performed in some alternative vessel. In these circumstances it is envisaged that the organic substance can be delivered by means of slow release from the bowl, bucket or other vessel which is being employed, or from any implement which is being employed, such as a brush, bat or dolly, or from any suitable applicator.
Suitable pre-treatment means for application of the organic substance to the textile material prior to the main wash include sprays, pens, roller-ball devices, bars, soft solid applicator sticks and impregnated cloths or cloths containing microcapsules. Such means are well known in the analogous art of deodorant application and/or in spot treatment of textiles. Similar means for application are employed in those embodiments where the organic substance is applied after the main washing and/or conditioning steps have been performed, e.g. prior to or after ironing or drying of the cloth. For example, the organic substance may be applied using tapes, sheets or sticking plasters coated or impregnated with the substance, or containing microcapsules of the substance. The organic substance may for example be incorporated into a drier sheet so as to be activated or released during a tumble-drier cycle, or the substance can be provided in an impregnated or microcapsule-containing sheet so as to be delivered to the textile when ironed.
Many transition metal complexes have high extinction coefficients in the visible. In this regard, use over time may result in some colour deposition on a substrate after repeated washing. The addition of a limited amount of a peroxyl source serves to reduce colour deposition in those instances in which it occurs whilst still permitting xe2x80x9cair bleachingxe2x80x9d. Nevertheless, we have found that in certain instances the free ligand may be used in the bleaching composition of the present invention. By using a free ligand, a bleaching formulation may prepared that is consistent with consumer formulation colour expectation. In such a formulation the metal ion may be provided by the composition or by trace metals found in the stain.